• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.27 no.4
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• pp.311-323
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• 2023

This paper introduces the industrial problem, the solution, and the results of the research conducted with Define Inc. The client company wanted to improve the performance of an object detection model on the floor plan dataset. To solve the problem, we analyzed the operational principles, advantages, and disadvantages of the existing object detection model, identified the characteristics of the floor plan dataset, and proposed to use of YOLO v5 as an appropriate object detection model for training the dataset. We compared the performance of the existing model and the proposed model using mAP@60, and verified the object detection results with real test data, and found that the performance increase of mAP@60 was 0.08 higher with a 25% shorter inference time. We also found that the training time of the proposed YOLO v5 was 71% shorter than the existing model because it has a simpler structure. In this paper, we have shown that the object detection model for the floor plan dataset can achieve better performance while reducing the training time. We expect that it will be useful for solving other industrial problems related to object detection in the future. We also believe that this result can be extended to study object recognition in 3D floor plan dataset.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.663-668
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• 1991

In order to navigate, mobile robot needs to avoid obstacles on his way. We describe a stereo vision method for detecting obstacles on the floor ground. With the knowledge of floor geometry, stereo images are transformed so that the relative views of obstacle to the floor are seen. After comparing the transformed images, obstacles information such as location and size are extracted and determined from the local disparities. Some experimental results are shown.

• Journal of IKEEE
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• v.18 no.1
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• pp.134-139
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• 2014

According to survey, more than 57.2% of the fall which is the most frequent safety accident of the elders takes place at home. This research aims to verify the fall by measuring and analyzing the floor vibration. And the vibration sensor module was designed with piezo film sensor and operation amplifier. The vibration signals are converted to digital signals through the data acquisition device and vibration sensor module. And then modified the signals into frequency domain to obtain characteristic vibration data. The characteristic signals are verified by K-Nearest Neighbor verification, and experimental results shows the recognition rate 93.6%. Also the fall detection sensor module is useful for extract the meaningful data for fall detection. 10 persons are participated for this experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.9
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• pp.858-862
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• 2015

This paper presents a new forward-viewing mono-camera based obstacle detection algorithm for mobile robots. The proposed method extracts the coarse location of an obstacle in an image using inverse perspective mapping technique from sequential images. In the next step, graph-cut based image labeling is conducted for estimating the exact obstacle boundary. The graph-cut based labeling algorithm labels the image pixels as either obstacle or floor as the final outcome. Experiments are performed to verify the obstacle detection performance of the developed algorithm in several examples, including a book, box, towel, and flower pot. The low illumination condition, low color contrast between floor and obstacle, and floor pattern cases are also tested.

• Journal of the Korean Association of Geographic Information Studies
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• v.6 no.3
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• pp.95-106
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• 2003

This study evaluated the architectural density of urban district using airborne laser scanning(ALS) that is a method used in urban planning, water resources and disaster prevention with high interest recently. First, digital elevation model(DEM) and digital surface model(DSM) was constructed from Light detection and ranging(LiDAR). For getting the height of building, ZONALMEAN filter was used in DEM and ZONALMAJORITY filter was used in DSM. This study compared the floor from filtering with the floor from survey and got standard error, which is ${\pm}0.199$ floor. Also, through the overlay and statistical analysis of total-area layer and zone layer, we could present floor area ratio by zone. As a result of comparison with floor area ratio between airborne laser scanning data and survey data, the standard error of floor area ratio shows ${\pm}2.68%$. Therefore, we expect that airborne laser scanning data can be a very efficient source to decision makers who set up landuse plan in near future.

• Smart Structures and Systems
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• v.14 no.4
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• pp.595-615
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• 2014

This study aims to investigate the relationship between structural damage and sensitivity indices using the Hilbert-Huang transform (HHT) method. Two damage detection indices are proposed: the ratio of bandwidth (RB), and the ratio of effective stiffness (RES). The nonlinear four bays multiple degree of freedom models with various predominant frequencies are constructed using the SAP2000 program. Adjusted PGA earthquake data (Japan 311, Chi-Chi 921) are used as the excitations. Next the damage detection indices obtained using the HHT and the fast Fourier transform (FFT) methods are evaluated based on the acceleration responses of the structures to earthquakes. Simulation results indicate that, the column of the 1 st floor is the first yielding position and the RB value is changed when the RES<90% in all cases. Moreover, the RB value of the 1 st floor changes more sensitive than those from the top floor. In addition, when the structural response is nonlinear (i.e., RES<100%), the RB and the RES curves indicate the incremental change in the HHT spectra. However, the same phenomenon can be found from FFT spectra only when the stiffness reduction is large enough. Therefore, the RB estimated from the smoothed HHT spectra is an effective and sensitive index for detecting structural damage.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.105-116
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• 2011

With recent spotlight on the, uniquitous computing technology, the need for object of indentification and location infrastructure has increased. Such GPS technolgy must utilize IEEE 802.15.4 Zigbee used for existing wireless sensor network infra as a basice element for user's context-awareness in a uniquitous environement, for effectiveness.Such real-time GPS service is provided in the internal environment where the user would actually are and most high-rise buildlings apply. Underthe assumption, the real-time GPS technology is seperated by each floor, and signals do not get transmitted to other floors, the application on one floor within the high-rise buildling was conducted. This study intends to suggest a floor detection algorithm using IEE 802.15.3/Zigbee's RSSI which supports the accuracy within a couple of meters for the user's the movement between the floors in high-rise buildings in a complex environment. It proposes an floor detection algorithm using IEEE 802.15.4/Zigbee's RSSI which provides accuracy within a radius of few meters for the users movement between the floors for real-time location tracking within high-rise building in a cmoplex environment. Furthermore, for more accurate real-time location tracking, it suggests an algorithm for real-time location tracking using IEEE 802.15.4a/Zigbee's CSS technology based on triangulation. Based on the suggested algorithm, it designs a hybrid real-time location tracking service system in a high-rise buildling and test its functions.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.125-132
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• 1993

When a mobile robot moves around autonomously without man-made landmarks, it is essential to recognize the placement of surrounding objects especially for current position estimation, obstacle avoidance, or homing into the work station. In this paper, we propose a novel approach to recognize the floor paln for indoor mobile robot navigation using ultrasonic time-of-flight method. We model the floor plan as a collection of polygonal plane objects and recognize the floor plan by locating edges and vertices of the objects. The direction is estimated by the patterns of transmission beam and reception sensitivity of the ultrasonic transducer, and the distance is estimated by the correlation detection method. We show the validity of the proposed approach through experimental results and discuss the resolution and the accuracy of the estimation of direction and distance.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.82-89
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• 1993

In order to detection of the intestinal parasites, fecal samples were taken from broiler (n=262), laying hen(n=244), parent stock(n=207) and native stock(n=287) in Chonbuk province. The prevalence and identification of intestinal parasites were determined by the fecal examination using the floatation and /or sedimentation methods and microscopical examination, respectively. The results were obtained as follows : 1. The detection rate of parasite-eggs from 4 flocks(total=1,000) was 65.7%. 2. In the breed and type of breeding, infection rate of parasite-eggs was detected 84.0％ as native stock (floor breeding, 241 chicken), 79.7％ as parent stock (floor breeding, 165 chickens), 73.3% as broiler(floor breeding, 192 chicken) and 24.2% as laying hen(cage breeding, 59 chicken), in order. 3. In the concern of mixed infection such as single, double and triple, the rate was 55.1%, 8.7% and 1.9%, respectively. 4. Ten kinds of infective eggs were isolated from 657 fecal sample of 4 flock. They were classified 51.l% as Eimeria spp., 12.7% as Ascaridia galli, 5.1% as Capillaria spp., 4.1% as Strongyloides avium, 2.3% as Heterakis gallinarum, 0.5% as Hymenolepis spp., 0.3% as Railleina spp. and 0.2% as Syngamus spp., Trichostrongilus spp., or Choanoteania spp., single or in combination.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.12-16
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• 2011

Building Information Modeling (BIM) is being widely spread in AEC industry worldwide and also in South Korea. Although the creation of digital model is better to be started at design stage, it can also improve the productivity of construction by simulating the actual construction process and environment. This paper presents application of BIM-based simulations related with design changes to transfer floors in 58-storey reinforced concrete office building. Transfer floor is not only a structurally important part of the building but also a challenging part of the actual construction in terms of sequence and period due to the complexity of the work. Preconstruction of rebar, mechanical, and plumbing is performed to review the construction drawings and to perform clash detection. Each item of application is evaluated for its effectiveness on actual construction and for the development potential.